summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-spear.c
blob: e2785479113ca06648949d6c6a78adee92c78367 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
/*
 * drivers/rtc/rtc-spear.c
 *
 * Copyright (C) 2010 ST Microelectronics
 * Rajeev Kumar<rajeev-dlh.kumar@st.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

/* RTC registers */
#define TIME_REG		0x00
#define DATE_REG		0x04
#define ALARM_TIME_REG		0x08
#define ALARM_DATE_REG		0x0C
#define CTRL_REG		0x10
#define STATUS_REG		0x14

/* TIME_REG & ALARM_TIME_REG */
#define SECONDS_UNITS		(0xf<<0)	/* seconds units position */
#define SECONDS_TENS		(0x7<<4)	/* seconds tens position */
#define MINUTES_UNITS		(0xf<<8)	/* minutes units position */
#define MINUTES_TENS		(0x7<<12)	/* minutes tens position */
#define HOURS_UNITS		(0xf<<16)	/* hours units position */
#define HOURS_TENS		(0x3<<20)	/* hours tens position */

/* DATE_REG & ALARM_DATE_REG */
#define DAYS_UNITS		(0xf<<0)	/* days units position */
#define DAYS_TENS		(0x3<<4)	/* days tens position */
#define MONTHS_UNITS		(0xf<<8)	/* months units position */
#define MONTHS_TENS		(0x1<<12)	/* months tens position */
#define YEARS_UNITS		(0xf<<16)	/* years units position */
#define YEARS_TENS		(0xf<<20)	/* years tens position */
#define YEARS_HUNDREDS		(0xf<<24)	/* years hundereds position */
#define YEARS_MILLENIUMS	(0xf<<28)	/* years millenium position */

/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
#define SECOND_SHIFT		0x00		/* seconds units */
#define MINUTE_SHIFT		0x08		/* minutes units position */
#define HOUR_SHIFT		0x10		/* hours units position */
#define MDAY_SHIFT		0x00		/* Month day shift */
#define MONTH_SHIFT		0x08		/* Month shift */
#define YEAR_SHIFT		0x10		/* Year shift */

#define SECOND_MASK		0x7F
#define MIN_MASK		0x7F
#define HOUR_MASK		0x3F
#define DAY_MASK		0x3F
#define MONTH_MASK		0x7F
#define YEAR_MASK		0xFFFF

/* date reg equal to time reg, for debug only */
#define TIME_BYP		(1<<9)
#define INT_ENABLE		(1<<31)		/* interrupt enable */

/* STATUS_REG */
#define CLK_UNCONNECTED		(1<<0)
#define PEND_WR_TIME		(1<<2)
#define PEND_WR_DATE		(1<<3)
#define LOST_WR_TIME		(1<<4)
#define LOST_WR_DATE		(1<<5)
#define RTC_INT_MASK		(1<<31)
#define STATUS_BUSY		(PEND_WR_TIME | PEND_WR_DATE)
#define STATUS_FAIL		(LOST_WR_TIME | LOST_WR_DATE)

struct spear_rtc_config {
	struct rtc_device *rtc;
	struct clk *clk;
	spinlock_t lock;
	void __iomem *ioaddr;
	unsigned int irq_wake;
};

static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
{
	unsigned int val;
	unsigned long flags;

	spin_lock_irqsave(&config->lock, flags);
	val = readl(config->ioaddr + STATUS_REG);
	val |= RTC_INT_MASK;
	writel(val, config->ioaddr + STATUS_REG);
	spin_unlock_irqrestore(&config->lock, flags);
}

static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
{
	unsigned int val;

	val = readl(config->ioaddr + CTRL_REG);
	if (!(val & INT_ENABLE)) {
		spear_rtc_clear_interrupt(config);
		val |= INT_ENABLE;
		writel(val, config->ioaddr + CTRL_REG);
	}
}

static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
{
	unsigned int val;

	val = readl(config->ioaddr + CTRL_REG);
	if (val & INT_ENABLE) {
		val &= ~INT_ENABLE;
		writel(val, config->ioaddr + CTRL_REG);
	}
}

static inline int is_write_complete(struct spear_rtc_config *config)
{
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&config->lock, flags);
	if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
		ret = -EIO;
	spin_unlock_irqrestore(&config->lock, flags);

	return ret;
}

static void rtc_wait_not_busy(struct spear_rtc_config *config)
{
	int status, count = 0;
	unsigned long flags;

	/* Assuming BUSY may stay active for 80 msec) */
	for (count = 0; count < 80; count++) {
		spin_lock_irqsave(&config->lock, flags);
		status = readl(config->ioaddr + STATUS_REG);
		spin_unlock_irqrestore(&config->lock, flags);
		if ((status & STATUS_BUSY) == 0)
			break;
		/* check status busy, after each msec */
		msleep(1);
	}
}

static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
{
	struct spear_rtc_config *config = dev_id;
	unsigned long flags, events = 0;
	unsigned int irq_data;

	spin_lock_irqsave(&config->lock, flags);
	irq_data = readl(config->ioaddr + STATUS_REG);
	spin_unlock_irqrestore(&config->lock, flags);

	if ((irq_data & RTC_INT_MASK)) {
		spear_rtc_clear_interrupt(config);
		events = RTC_IRQF | RTC_AF;
		rtc_update_irq(config->rtc, 1, events);
		return IRQ_HANDLED;
	} else
		return IRQ_NONE;

}

static int tm2bcd(struct rtc_time *tm)
{
	if (rtc_valid_tm(tm) != 0)
		return -EINVAL;
	tm->tm_sec = bin2bcd(tm->tm_sec);
	tm->tm_min = bin2bcd(tm->tm_min);
	tm->tm_hour = bin2bcd(tm->tm_hour);
	tm->tm_mday = bin2bcd(tm->tm_mday);
	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
	tm->tm_year = bin2bcd(tm->tm_year);

	return 0;
}

static void bcd2tm(struct rtc_time *tm)
{
	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
	/* epoch == 1900 */
	tm->tm_year = bcd2bin(tm->tm_year);
}

/*
 * spear_rtc_read_time - set the time
 * @dev: rtc device in use
 * @tm: holds date and time
 *
 * This function read time and date. On success it will return 0
 * otherwise -ve error is returned.
 */
static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct spear_rtc_config *config = dev_get_drvdata(dev);
	unsigned int time, date;

	/* we don't report wday/yday/isdst ... */
	rtc_wait_not_busy(config);

	time = readl(config->ioaddr + TIME_REG);
	date = readl(config->ioaddr + DATE_REG);
	tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
	tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
	tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
	tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
	tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
	tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;

	bcd2tm(tm);
	return 0;
}

/*
 * spear_rtc_set_time - set the time
 * @dev: rtc device in use
 * @tm: holds date and time
 *
 * This function set time and date. On success it will return 0
 * otherwise -ve error is returned.
 */
static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct spear_rtc_config *config = dev_get_drvdata(dev);
	unsigned int time, date, err = 0;

	if (tm2bcd(tm) < 0)
		return -EINVAL;

	rtc_wait_not_busy(config);
	time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
		(tm->tm_hour << HOUR_SHIFT);
	date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
		(tm->tm_year << YEAR_SHIFT);
	writel(time, config->ioaddr + TIME_REG);
	writel(date, config->ioaddr + DATE_REG);
	err = is_write_complete(config);
	if (err < 0)
		return err;

	return 0;
}

/*
 * spear_rtc_read_alarm - read the alarm time
 * @dev: rtc device in use
 * @alm: holds alarm date and time
 *
 * This function read alarm time and date. On success it will return 0
 * otherwise -ve error is returned.
 */
static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct spear_rtc_config *config = dev_get_drvdata(dev);
	unsigned int time, date;

	rtc_wait_not_busy(config);

	time = readl(config->ioaddr + ALARM_TIME_REG);
	date = readl(config->ioaddr + ALARM_DATE_REG);
	alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
	alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
	alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
	alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
	alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
	alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;

	bcd2tm(&alm->time);
	alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;

	return 0;
}

/*
 * spear_rtc_set_alarm - set the alarm time
 * @dev: rtc device in use
 * @alm: holds alarm date and time
 *
 * This function set alarm time and date. On success it will return 0
 * otherwise -ve error is returned.
 */
static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct spear_rtc_config *config = dev_get_drvdata(dev);
	unsigned int time, date, err = 0;

	if (tm2bcd(&alm->time) < 0)
		return -EINVAL;

	rtc_wait_not_busy(config);

	time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
			MINUTE_SHIFT) |	(alm->time.tm_hour << HOUR_SHIFT);
	date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
			MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);

	writel(time, config->ioaddr + ALARM_TIME_REG);
	writel(date, config->ioaddr + ALARM_DATE_REG);
	err = is_write_complete(config);
	if (err < 0)
		return err;

	if (alm->enabled)
		spear_rtc_enable_interrupt(config);
	else
		spear_rtc_disable_interrupt(config);

	return 0;
}

static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct spear_rtc_config *config = dev_get_drvdata(dev);
	int ret = 0;

	spear_rtc_clear_interrupt(config);

	switch (enabled) {
	case 0:
		/* alarm off */
		spear_rtc_disable_interrupt(config);
		break;
	case 1:
		/* alarm on */
		spear_rtc_enable_interrupt(config);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static struct rtc_class_ops spear_rtc_ops = {
	.read_time = spear_rtc_read_time,
	.set_time = spear_rtc_set_time,
	.read_alarm = spear_rtc_read_alarm,
	.set_alarm = spear_rtc_set_alarm,
	.alarm_irq_enable = spear_alarm_irq_enable,
};

static int __devinit spear_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct spear_rtc_config *config;
	unsigned int status = 0;
	int irq;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "no resource defined\n");
		return -EBUSY;
	}
	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
		dev_err(&pdev->dev, "rtc region already claimed\n");
		return -EBUSY;
	}

	config = kzalloc(sizeof(*config), GFP_KERNEL);
	if (!config) {
		dev_err(&pdev->dev, "out of memory\n");
		status = -ENOMEM;
		goto err_release_region;
	}

	config->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(config->clk)) {
		status = PTR_ERR(config->clk);
		goto err_kfree;
	}

	status = clk_enable(config->clk);
	if (status < 0)
		goto err_clk_put;

	config->ioaddr = ioremap(res->start, resource_size(res));
	if (!config->ioaddr) {
		dev_err(&pdev->dev, "ioremap fail\n");
		status = -ENOMEM;
		goto err_disable_clock;
	}

	spin_lock_init(&config->lock);
	platform_set_drvdata(pdev, config);

	config->rtc = rtc_device_register(pdev->name, &pdev->dev,
			&spear_rtc_ops, THIS_MODULE);
	if (IS_ERR(config->rtc)) {
		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
				PTR_ERR(config->rtc));
		status = PTR_ERR(config->rtc);
		goto err_iounmap;
	}

	/* alarm irqs */
	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no update irq?\n");
		status = irq;
		goto err_clear_platdata;
	}

	status = request_irq(irq, spear_rtc_irq, 0, pdev->name, config);
	if (status) {
		dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \
				claimed\n", irq);
		goto err_clear_platdata;
	}

	if (!device_can_wakeup(&pdev->dev))
		device_init_wakeup(&pdev->dev, 1);

	return 0;

err_clear_platdata:
	platform_set_drvdata(pdev, NULL);
	rtc_device_unregister(config->rtc);
err_iounmap:
	iounmap(config->ioaddr);
err_disable_clock:
	clk_disable(config->clk);
err_clk_put:
	clk_put(config->clk);
err_kfree:
	kfree(config);
err_release_region:
	release_mem_region(res->start, resource_size(res));

	return status;
}

static int __devexit spear_rtc_remove(struct platform_device *pdev)
{
	struct spear_rtc_config *config = platform_get_drvdata(pdev);
	int irq;
	struct resource *res;

	/* leave rtc running, but disable irqs */
	spear_rtc_disable_interrupt(config);
	device_init_wakeup(&pdev->dev, 0);
	irq = platform_get_irq(pdev, 0);
	if (irq)
		free_irq(irq, pdev);
	clk_disable(config->clk);
	clk_put(config->clk);
	iounmap(config->ioaddr);
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res)
		release_mem_region(res->start, resource_size(res));
	platform_set_drvdata(pdev, NULL);
	rtc_device_unregister(config->rtc);
	kfree(config);

	return 0;
}

#ifdef CONFIG_PM

static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct spear_rtc_config *config = platform_get_drvdata(pdev);
	int irq;

	irq = platform_get_irq(pdev, 0);
	if (device_may_wakeup(&pdev->dev)) {
		if (!enable_irq_wake(irq))
			config->irq_wake = 1;
	} else {
		spear_rtc_disable_interrupt(config);
		clk_disable(config->clk);
	}

	return 0;
}

static int spear_rtc_resume(struct platform_device *pdev)
{
	struct spear_rtc_config *config = platform_get_drvdata(pdev);
	int irq;

	irq = platform_get_irq(pdev, 0);

	if (device_may_wakeup(&pdev->dev)) {
		if (config->irq_wake) {
			disable_irq_wake(irq);
			config->irq_wake = 0;
		}
	} else {
		clk_enable(config->clk);
		spear_rtc_enable_interrupt(config);
	}

	return 0;
}

#else
#define spear_rtc_suspend	NULL
#define spear_rtc_resume	NULL
#endif

static void spear_rtc_shutdown(struct platform_device *pdev)
{
	struct spear_rtc_config *config = platform_get_drvdata(pdev);

	spear_rtc_disable_interrupt(config);
	clk_disable(config->clk);
}

#ifdef CONFIG_OF
static const struct of_device_id spear_rtc_id_table[] = {
	{ .compatible = "st,spear600-rtc" },
	{}
};
MODULE_DEVICE_TABLE(of, spear_rtc_id_table);
#endif

static struct platform_driver spear_rtc_driver = {
	.probe = spear_rtc_probe,
	.remove = __devexit_p(spear_rtc_remove),
	.suspend = spear_rtc_suspend,
	.resume = spear_rtc_resume,
	.shutdown = spear_rtc_shutdown,
	.driver = {
		.name = "rtc-spear",
		.of_match_table = of_match_ptr(spear_rtc_id_table),
	},
};

module_platform_driver(spear_rtc_driver);

MODULE_ALIAS("platform:rtc-spear");
MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
MODULE_LICENSE("GPL");